1. Field of the Invention
The invention relates to a valve control for adjusting the stroke of valves of a motor vehicle engines, the valve control comprising at least one adjusting shaft with which a valve shaft of the valve can be moved by means of at least one transmitting chain.
2. Description of the Related Art
Valve controls used in connection with internal combustion engines are known which vary the valve stroke in a continuous fashion in order to lower the fuel consumption. The valve controls control the valve stroke as a function of the motor output or power so that always only that amount of fuel is injected into the combustion chamber of the cylinder as required for the momentary output demand. In a known valve control an electric motor is provided whose pinion interacts with an adjusting wheel mounted on an adjusting shaft. By means of this adjusting shaft, the transmission geometry between the camshaft and the valve is changed such that different valve strokes can be adjusted. However, this valve control is extremely complex and accordingly expensive to manufacture.
It is an object of the present invention to configure the valve control of the aforementioned kind such that the valve stroke can be adjusted easily while an inexpensive configuration is realized.
In accordance with the present invention, this is achieved in that the adjusting shaft can be rotated about its axis to a limited extent by at least one hydraulic drive.
In the valve control according to the invention, the adjusting shaft is rotated by the hydraulic drive such that the valve stroke can be adjusted as a function of the momentarily required output of the motor. The valve control according to the invention operates preferably completely variably so that within the adjusting range any desired valve stroke can be adjusted. The hydraulic drive can be realized in a simple and inexpensive way and provides a problem-free use.